A mason jar baby bottle lid includes a metal threaded mason jar collar and a bottle nipple formed of a flexible and non-toxic material. The bottle nipple has a domed body portion having a nipple projecting from an upper end of the domed body, a flange including an upward-projecting lip formed on the lower end of the domed body, and an annular indentation formed between the flange and the domed body of the bottle nipple and including an overhang surface. A height of the upwardly protruding lip of the flange is such that when the bottle nipple is engaged with the mason jar collar, the overhang surface is adjacent the substantially flat upper surface of the collar.
